Machine for sharpening drills



Oct. 6, 1959 H. HEUSI MACHINE FOR SHARPENING DRILLS Filed l lay 6, 1958 United States Patent MACHINE FOR SHARPENING DRILLS Hans Heusi, Bienne, Switzerland, assignor to Christen '5'; Co. S.A., Bern, Switzerland, a Swiss firm Application May 6, 1958, Serial No. 733,366

Claims priority, application Germany May 16, 1957 1 Claim. (Cl. 51-219) The present invention has for its object an improvement in or a modification of a prior machine for sharpening or grinding drills and the like tools of the type disclosed in Patent No. 2,866,302 assigned to the same assignee as the present specification; said machine includes a frame, a carrier mounted in the latter, soas to be capable of rocking round its axis in a plane perpendicular to the latter and a headstock secured to said carrier and in which the drill is mounted so as to be capable of revolving round its axis, the drill and the grinding wheel being adapted to be shifted in a manner such that when they are brought into their relative operative position, the above-mentioned axis on which the tip of the drill is located lies in the operative plane of the grinding wheel, while the headstock is mounted on the carrier in a manner such that it may execute a movement which does not substantially modify the direction of the axis of the drill and is adapted to shift reciprocatingly said drill towards and away from the grinding Wheel and a mechanism is adapted to associate the movement of the drill either with the above-mentioned first rocking movement of the headstock or with both movements of the latter, said mechanism controlling further means for adjusting the amplitude and the point of origin of both said movements of the headstock.

In a preferred embodiment, the grinding wheel is carried by an arm rocking with reference to the frame round an axis parallel with the axis of the grinding wheel. Now according to my present invention, I ensure, in such a machine the grinding of helical drills, whether with a left-handed pitch or with a right-handed pitch under similar practical conditions. It has been found, in fact, in operation that it would be desirable when grinding left-handed drills to provide a suflicient space between the supporting frame or body and the rocking arm, while the stationary stop ensuring the rocking of the head stock is shifted rearwardly on the frame carrying it as far as possible and even onto the rear surface of the said frame; thus, it is possible to obtain an easy access to said stationary stop and to bring it without any difiiculty into its operative position. The machine ac cording to the present invention allows satisfying said conditions by securing the rocking arm carrying the grinding wheel at the end of a lateral support, so that there remains sufficient room between it and the frame of the machine, whereby it is possible to obtain an easy access to said stationary stop and to readily shift the latter when it is desired to obtain the sharpening or grinding of drills with a left-handed pitch.

The single figure of the accompanying drawing shows a preferred embodiment of the invention.

The machine includes a central frame or body 12 and a lateral cylindrical support 3 thereon, on which support is revolubly fitted a rocking arm 4 with the motor 5 driving the grinding wheel 6. A control system of which only the handwheel 7 is shown in the ICC drawing allows rocking the whole system including the rocking arm 4, the motor 5 and the grinding wheel 6 round the axis 41: extending inside the support 3 in parallelism with the axis of the grinding wheel. The machine is furthermore provided with a spindle-carrying headstock 11 in which the spindle 12 is fitted with the drill to be sharpened or ground. Said spindle carrying headstock may rock round the vertical axis 10 of the body 1 of the machine, between two terminal positions which are angularly spaced by equal amounts and to a sufiicient extent with reference to the plane defined by the axis 4a and the axis 10 of the support 1. Thus, the grinding of right-handed grooves may be executed on one side of said plane and that of left-handed grooves on the other side. The spindle-carrying headstock is illustrated in the drawing in a position corresponding to the grinding of a left-handed groove.

The novelty of the machine illustrated consists in the location of the rocking arm 4 at the outer end of the lateral support 3 for the operative position of the grinding wheel.

This arrangement allows, when grinding a left-handed helical drill, bringing into its operative position the stop 49 cooperating with the projection 48 for the rocking of the headstock; in said Patent No. 2,866,302 said stop being positioned if not exactly to the rear of the body 1, at least near said rear part.

Furthermore, the access to said stop 49 is substantially improved by reason of the presence of the empty space formed by the body 1, the support 3, the rocking arm 4 and the casing 5a6a carrying the grinding wheel and its driving motor.

What I claim is:

A machine for grinding left-handed and right-handed drills under similar conditions of operation, comprising a vertical cylindrical body, a spindle adapted to carry a drill, a headstock carrying said spindle and carried by said body to rock round a vertical axis within an angular sector extending to either side of a predetermined vertical plane passing through said axis, a transverse horizontal support rigid with the body and extending in a direction diametrically opposed to the medial position of the headstock in its angular sector of movement and a rotary support carried by the outer end of said support at a substantial distance from said first-mentioned axis to rock round a horizontal axis lying in said vertical plane and extending inside the transverse support, said rotary support being spaced by a large gap with reference to the body, a grinding wheel carried by said rotary support at a substantial distance above said transverse support in registry with the location of the' drill carried by the spindle in the headstock, an arrangement controlling the setting of the spindle in the headstock, and facing the gap between the rotary support and the body on the side of the latter opposed to the rotary support a stationary stop carried by the body in horizontal registry with last-mentioned gap between said body and the rotary support and facing the latter near said vertical plane and adjustable in the latter to either side of the vertical plane and means carried by the headstock and adapted to engage the stop to cooperate therewith in the rocking movement of the headstock round its vertical axis.

References Cited in the file of this patent UNITED STATES PATENTS 2,713,755 Ganahl July 26, 1955 FOREIGN PATENTS 260,150 Switzerland Feb, 28, 1949 

